Which organism is predominant in normal vaginal flora?

Lactobacillus is the predominant organism in normal vaginal flora. It plays a crucial role in maintaining a healthy vaginal environment through the production of lactic acid, which helps to lower the pH of the vagina. This acidic environment is important because it inhibits the growth of pathogenic organisms, thereby providing protection against infections.

Lactobacillus also helps to maintain the balance of the vaginal microbiome, supporting the overall health of the reproductive system. A healthy population of Lactobacillus is essential for preventing conditions such as bacterial vaginosis and yeast infections, which can occur when the normal flora is disrupted and harmful pathogens can proliferate.

Other organisms listed, while present in the vagina, do not constitute the predominant flora. Staphylococcus, for example, is more commonly associated with skin flora. Escherichia coli is often linked to urinary tract infections but is not a major component of normal vaginal flora. Gardnerella vaginalis is often associated with bacterial vaginosis but is typically present in lower quantities compared to Lactobacillus in a healthy vagina.